The present invention relates to emergency devices and methods for ventilating patients, particularly to laryngoscope handles and devices for securing a mask or endotracheal tube to a patient to provide ventilation.
Note that herein all references made to “oxygen” are to be understood to include “air” as well.
Conventional masks used to supply oxygen to a patient are fitted over the nose and mouth of the patient and typically use one or more elastic bands placed behind the patient's ears or around the head to secure the mask to the patient's face. Oxygen is fed into the mask through a tube.
One commonly-used type of ventilation device utilizing a mask is a bag-valve-mask, also called a BVM. The bag-valve-mask is a hand-held device used to provide ventilation to a patient who is not breathing or who is breathing inadequately. The bag-valve-mask is a normal part of a resuscitation kit for trained professionals, such as ambulance crews. The bag-valve-mask is also frequently used in hospitals and is an essential part of a crash cart.
The bag-valve-mask consists of a flexible air chamber attached to a mask via a shutter valve. When the air chamber or “bag” is squeezed, the device forces air through the mask and into the patient's lungs. When the bag is released it self-inflates, drawing in either ambient air or a low pressure oxygen flow supplied from a regulated cylinder. In response, the patient's lungs deflate through the one way valve.
A bag-valve-mask without the mask is called a bag-and-valve combination. The bag-and-valve combination, absent the mask, can be attached to an alternate airway adjunct, such as an endotracheal tube. In this way, an endotracheal tube can be used in place of a mask, as discussed below.
When ventilating a patient using a mask, the mask is positioned and secured over the patient's nose and mouth to obtain a good seal so as to ensure oxygen does not escape from around the mask. One common method for obtaining a seal is called a “CE” clamp formation. The CE clamp formation involves using the index finger and thumb on the mask, forming a “C,” and remaining on the jaw line, forming an “E,” to secure the mask to the patient. A proper CE clamp can be even more difficult to maintain if the caregiver with smaller hands is required to provide adequate oxygen flow or tidal volume through the use of a bag-valve-mask or similar device. Other factors can also interfere with providing an effective seal around a mask, such as the position of accident victims, as when in an upright seated position.
During surgery, and in emergency situations, it may become necessary to intubate a patient. This is particularly true in emergency situations where a patient's mouth, throat, or tracheal passage becomes blocked by blood, mucus, or other obstruction. Intubation is the process of inserting an endotracheal tube into the trachea of the patient to provide a clear airway to the patient's lungs. Oxygen is then supplied through the tube. Intubation usually requires general anesthesia and muscle relaxation, but can be achieved in a conscious patient with anesthesia. In an emergency situation, intubation can be performed without anesthesia, although this is uncomfortable for the patient. Intubation is usually performed by first visualizing the larynx using a handheld laryngoscope.
The laryngoscope is typically comprised of two parts, a handle and a removable blade. The handle is typically made of metal and in the approximate shape of an elongated cylinder with a hollow chamber for holding batteries to power a light commonly found on the blade. The removable blade is elongated and generally made of metal. The two main types of blades used in a laryngoscope are curved blades and straight blades. A base of the blade attaches to a top of the handle, with the base of the blade aligned basically perpendicular to the handle.
To begin intubation, a blade is selected and connected to the laryngoscope handle. The handle and blade are then used to visualize the larynx so that the patient can be intubated. The caregiver first opens the patient's mouth and inserts a tip of the blade into the mouth and slides the blade to the base of the tongue. Given the angle of the blade to the handle, the handle will be transverse to the mouth as the blade is inserted. This partially obscures the caregiver's view of the mouth, which sometimes results in the caregiver striking and damaging the patient's teeth or lip with the blade. To bring the larynx into view, the patient's chin is lifted upwards and forward at the same time. The blade is then properly located in the patient's mouth with the precise location dependent upon the type of blade used. With the blade properly positioned, the caregiver can now apply a degree of force to the handle to lift the patient's upper jaw. The handle is raised upwardly and away from the patient to an angle of approximately forty-five degrees relative to the patient's mandible. At this point, the larynx should come into view.
A common technique used by caregivers in raising upwardly on the handle is to grip the handle near the blade so as to have more control over the blade and then twisting the wrist to pull the handle upwardly. Again, the shape of the handle can obscure the caregiver's view of the trachea as the handle is transverse to the mouth. Sometimes this twisting of the wrist can lead to a tendency to use the teeth as a fulcrum for the laryngoscope, which can cause damage to the teeth.
Once the larynx is in view, the endotracheal tube is placed through the mouth and down into the trachea between the vocal folds. An end of the endotracheal tube is equipped with an inflatable cuff. When a top end of the cuff clears the vocal folds, insertion of the endotracheal tube is halted and the cuff is inflated. The cuff provides a seal to prevent aspiration and leakage of oxygen. The laryngoscope is removed, and the opposite end of the endotracheal tube is attached to an oxygen source, such as a bag-and-valve combination.
It is now important that the endotracheal tube be secured in a stable position, likely for an extended period of time. Unintended movement of the endotracheal tube can harm delicate tissues in the patient's trachea. It is also important, especially in emergency situations, that the caregiver's hands remain free to perform other treatment.
Typically, tape is wrapped around the endotracheal tube and also attached to the facial area around the mouth to secure the endotracheal tube in place. Unfortunately, if the taping is done incorrectly the tube can move about in the patient's mouth and irritate the trachea. In addition, the very flexibility of the adhesive tape itself can permit some lateral movement of the endotracheal tube. Another concern is that saliva can collect on the tape and cause the tape to lose adhesion, requiring it to be reapplied. Such periodic reapplication can irritate the patient's skin. Making adjustments to the endotracheal tube also generally requires removal and reapplication of the tape. Removing the tape, however, cannot ordinarily be done rapidly, as might be necessary in an emergency situation. The tape also hinders access to the mouth area for such care as suctioning out the mouth.
As an alternative to tape, a tube-holding device can be used to secure the endotracheal tube in position. Many such devices exist in the prior art. Typically, after the endotracheal tube has been inserted through a patient's mouth and down into the trachea, a tube-holding device having a generally central opening is lowered over the tube. The device is secured over the mouth using adhesive tape, one or more bands wrapped about the patient's head, or some other way of fastening. The tube is then secured in position within the device by such means as adhesive tape or a clamp surrounding the central opening of the device. Other means for securing the endotracheal tube are also possible. For example, one prior art device uses a thumbscrew to contact the tube and thereby secure it. Some tube-holding devices also incorporate a bite block secured to a face plate. The face plate generally covers a substantial portion of the face around the patient's mouth while the bite block is inserted into the mouth. A disadvantage of the bite block is that it can sometimes cause trauma to the interior of the mouth.
There is a need, therefore, for a device that secures a mask to a patient's face in a manner that ensures a good seal around the mask in emergency situations and that frees up the hands of a caregiver to attend to other treatment needs. There is also a need for a device to secure an endotracheal tube to a patient in a manner that prevents substantial movement of the tube once installed, that allows for easy repositioning of the installed tube, and that offers a minimum of skin irritation and mouth trauma. There is a further need for a laryngoscope handle that allows for better viewing of the inside of the mouth so as to effect an easier installation of an endotracheal tube without causing undue injury, as well as a handle that provides better leverage for lifting the jaw, thereby relieving a tendency to use the teeth as a fulcrum and thus causing damage.